Bidirectional sidelink radio link control bearers

Abstract

Peer devices may wirelessly communicate with each other over a bidirectional sidelink logical channel (LCH) through an established bidirectional sidelink radio bearer. An initiating device of the peer devices may dynamically select a logical channel ID for establishing a fully bidirectional or semi-bidirectional SLRB. At least two alternative sidelink radio resource control (PC5-RRC) procedures may ensure the SLRB parameters are configured correctly in the established logical channel. The procedures also allow the network to configure a limited SLRB which is used to couple the SLRB configuration in the direction in which limited traffic (e.g. feedback information such as robust header compression feedback and/or status reports) is transmitted.

The invention claimed is: 
     
       1. An apparatus of a device comprising:
 a processor configured to perform operations comprising:
 selecting a first channel identifier (ID) to identify a single bidirectional logical channel corresponding to a bidirectional sidelink radio bearer (SLRB); 
 initiating a setup procedure to establish the bidirectional SLRB between the device and a peer device, using the first channel ID; 
 starting a timer in response to failing to establish the bidirectional SLRB with the peer device; 
 re-initiating the setup procedure upon expiration of the timer to establish the bidirectional SLRB; and 
 upon successfully establishing the bidirectional SLRB:
 transmitting data and feedback information to the peer device over the single bidirectional logical channel, wherein the feedback information comprises one or more of status reports or robust header compression feedback; and 
 receiving data and feedback information from the peer device over the single bidirectional logical channel. 
 
 
 
     
     
       2. The apparatus of  claim 1 , wherein re-initiating the setup procedure comprises using one of:
 the first channel ID; or 
 a second channel ID different from the first channel ID. 
 
     
     
       3. The apparatus of  claim 2 , the operations further comprising:
 using the second channel ID in response to detecting that the first channel ID has already been used by the peer device. 
 
     
     
       4. The apparatus of  claim 1 , wherein failing to establish the bidirectional SLRB with the peer device is at least in response to the peer device initiating a second setup procedure to establish the bidirectional SLRB between the peer device and the device at a same time as the processor initiating the setup procedure. 
     
     
       5. The apparatus of  claim 4 , wherein failing to establish the bidirectional SLRB with the peer device is further in response to the processor and the peer device both using the first channel ID when respectively initiating the setup procedure and the second setup procedure, but respectively using incompatible parameters corresponding to communications conducted over the bidirectional SLRB. 
     
     
       6. The apparatus of  claim 1 , wherein the setup procedure comprises:
 specifying respective values for one or more parameters from a plurality of parameters that include:
 an SLRB identification identifying the bidirectional SLRB; and 
 one from among an acknowledged mode and unacknowledged mode; and 
 
 configuring the peer device with the specified values via sidelink radio resource control signaling. 
 
     
     
       7. The apparatus of  claim 1 , the operations further comprising:
 receiving respective values of at least a subset of a first set of parameters from a serving base station, wherein the first set of parameters correspond to the single bidirectional logical channel. 
 
     
     
       8. The apparatus of  claim 7 , the operations further comprising:
 upon successfully establishing the bidirectional SLRB:
 transmitting information indicative of the respective values of the at least a subset of the first set of parameters to the peer device to configure the peer device. 
 
 
     
     
       9. A device comprising:
 radio circuitry configured to enable wireless communications of the device; and 
 a processor communicatively coupled to the radio circuitry and configured to perform operations comprising:
 selecting a first channel identifier (ID) to identify a single bidirectional logical channel corresponding to a bidirectional sidelink radio bearer (SLRB); 
 initiating a setup procedure to establish the bidirectional SLRB between the device and a peer device, using the first channel ID; 
 starting a timer in response to failing to establish the bidirectional SLRB with the peer device; re-initiating the setup procedure upon expiration of the timer to establish the bidirectional SLRB; and 
 upon successfully establishing the bidirectional SLRB:
 transmitting data and feedback information to the peer device over the single bidirectional logical channel, wherein the feedback information comprises one or more of status reports or robust header compression feedback; and 
 receiving data and feedback information from the peer device over the single bidirectional logical channel. 
 
 
 
     
     
       10. The device of  claim 9 , wherein re-initiating the setup procedure comprises using one of:
 the first channel ID; or 
 a second channel ID different from the first channel ID. 
 
     
     
       11. The device of  claim 10 , the operations further comprising:
 using the second channel ID in response to detecting that the first channel ID has already been used by the peer device. 
 
     
     
       12. The device of  claim 9 , wherein failing to establish the bidirectional SLRB with the peer device is at least in response to the peer device initiating a second setup procedure to establish the bidirectional SLRB between the peer device and the device at a same time as the processor initiating the setup procedure. 
     
     
       13. The device of  claim 12 , wherein failing to establish the bidirectional SLRB with the peer device is further in response to the processor and the peer device both using the first channel ID when respectively initiating the setup procedure and the second setup procedure, but respectively using incompatible parameters corresponding to communications conducted over the bidirectional SLRB. 
     
     
       14. The device of  claim 9 , wherein the setup procedure comprises:
 specifying respective values for one or more parameters from a plurality of parameters that include:
 an SLRB identification identifying the bidirectional SLRB; and 
 one from among an acknowledged mode and unacknowledged mode; and 
 configuring the peer device with the specified values via sidelink radio resource control signaling. 
 
 
     
     
       15. A non-transitory memory element storing instructions executable by a processor of a device to perform operations comprising:
 selecting a first channel identifier (ID) to identify a single bidirectional logical channel corresponding to a bidirectional sidelink radio bearer (SLRB); 
 initiating a setup procedure to establish the bidirectional SLRB between the device and a peer device, using the first channel ID; 
 starting a timer in response to failing to establish the bidirectional SLRB with the peer device; re-initiating the setup procedure upon expiration of the timer to establish the bidirectional SLRB; and 
 upon successfully establishing the bidirectional SLRB:
 transmitting data and feedback information to the peer device over the single bidirectional logical channel, wherein the feedback information comprises one or more of status reports or robust header compression feedback; and 
 receiving data and feedback information from the peer device over the single bidirectional logical channel. 
 
 
     
     
       16. The non-transitory memory element of  claim 15 , wherein re-initiating the setup procedure comprises using one of:
 the first channel ID; or 
 a second channel ID different from the first channel ID. 
 
     
     
       17. The non-transitory memory element of  claim 16 , the operations further comprising:
 using the second channel ID in response to detecting that the first channel ID has already been used by the peer device. 
 
     
     
       18. The non-transitory memory element of  claim 15 , wherein failing to establish the bidirectional SLRB with the peer device is at least in response to the peer device initiating a second setup procedure to establish the bidirectional SLRB between the peer device and the device at a same time as the processor initiating the setup procedure. 
     
     
       19. The non-transitory memory element of  claim 18 , wherein failing to establish the bidirectional SLRB with the peer device is further in response to the processor and the peer device both using the first channel ID when respectively initiating the setup procedure and the second setup procedure, but respectively using incompatible parameters corresponding to communications conducted over the bidirectional SLRB. 
     
     
       20. The non-transitory memory element of  claim 15 , wherein the setup procedure comprises:
 specifying respective values for one or more parameters from a plurality of parameters that include:
 an SLRB identification identifying the bidirectional SLRB; and 
 one from among an acknowledged mode and unacknowledged mode; and 
 configuring the peer device with the specified values via sidelink radio resource control signaling.